Background

The rationale behind this treatment approach is that systemic factors present in young blood cross into the brain, where they counteract aging processes and neurodegeneration by modulating neuroinflammation, neurogenesis, and cognitive function. In essence, this approach attempts to rejuvenate the aging brain with infusions of plasma from young adults. Initial clinical trials grew, in part, out of parabiosis studies, in which old mice connected via their circulatory systems to young mice showed improvements on a wide range of outcome measures related to aging and neurodegeneration (May 2014 conference news; Mar 2013 conference news; Nov 2009 conference news).

Findings

From September 2014 to February 2017, a double-blinded Phase 1 study at Stanford University enrolled 18 people with mild to moderate Alzheimer's disease into a 12-week trial. It compared a four-week treatment regimen of once-weekly injections of one unit of plasma from men aged 30 or under to placebo. Treatment and placebo groups switched off after a four-week washout. Safety was the primary outcome; other outcomes included cognitive, functional, and neuropsychiatric AD scales, as well as functional connectivity in the default mode network as per resting state functional MRI. At the 2017 CTAD meeting, the treatment was reported to have been safe and to have yielded a signal on functional/daily activities tests. However, two participants dropped out and the study switched to open-label midway through (Dec 2017 conference news). See clinicaltrials.gov.

In May 2015, a Phase 1 study at the University of California, San Francisco, enrolled six people with progressive supranuclear palsy into an open-label study of transfusion of plasma from blood donors 30 or younger. This study infuses four units of fresh frozen plasma once a month for six months. Beyond the primary outcome of safety, this trial lists 13 additional outcome measures ranging from change in motor, cognitive, functional, and behavioral measures to CSF, MRI, saccadic eye movement, and sleep measures. See clinicaltrials.gov.

In 2018, a second-generation approach to young plasma entered clinical trials, see GRF6019.